Improvement in watch-case springs



A. N. CLARK.

. Watch-Case Spring.

No. 196,786. Patented Nov. 6, I877.

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ALLISON N. CLARK, OF PLAINVILLE, CONNECTICUT.

IMPROVEMENT IN WATCH-CASE SPRINGS.

Specification forming part of Letters Patent No. 196,786, dated November 6, 1877 application filed September 14, 1877.

To all whom it may concern:

Be it known that I, ALLISON N. CLARK, of Plainville, in the county of Hartford and State of Connecticut,have invented certain new and useful Improvements in WVatch-Case Springs, of which the following is a specification:

My invention consists of a watch-case spring provided with one or more depressions upon its inside face, in combination with a fastening-pin resting in one of said depressions, as hereinafter described.

In the accompanying drawings, Figure lis a perspective view of a watch-case spring which embodies my invention. Fig. 2 is a side elevation of said spring, showing also a sectional view of the case within which the spring is secured. Fig. 3 is an enlarged view of a portion of the watclrcase, showing an edge view of the spring in broken lines underneath the rinrof the case.

The main portion of the spring is of a wellknown form, and is fitted within the case by dressing off its edges until they snugly fit the top and bottom rims of the case, as shown in Fig. 2. Upon the inside face of the body of the spring I form a depression or a series of depressions, a, which I prefer to make in the form of small transverse grooves, as shown.

The spring is placed in the case as repre sented in Fig. 2, and, when in proper position, slipped endwise enough to bring one of the depressions directly under the hole in the caserim, when the pin 1) is inserted. The side of the pin engages one of the depressions, and thereby prevents the spring from slipping endwise, while the outward pressure of the spring causes sufficient friction to hold the pin from accidental displacement; and, furthermore, the rim which receives the crystal, when in place, sets over the end of the pin, and firmly holds the pin in place. If desired, a screw might be substituted for the pin; but a pin is believed to answer all practical pinposes, and for some reasons is preferable.

By my improvement the spring is as firmly held from longitudinal movement as if a pin or screw passed from the case-rim into a hole in the body of the spring, while at the same time the spring may be set back of the hole in the case-rim, as shown in Fig. 3, and thereby be more out of the way.

I claim' as my invention The herein-described spring, having one or more depressions upon its inside face, in combination with the pin resting in one of said depressions, substantially as described, and for the purpose specified.

ALLISON N. CLARK.

WVitnesses GEO. D. CLARK, JAMES SHEPARD. 

